Volume 3 Issue 2 - 2018
Luke Del Vecchio,1 Hays Daewoud,1 Shannon Green2
1Department of Australian Combat & Exercise, Australia
2Department of Warrior Performance, Australia
This blog outlines some key points of Luke Del Vecchio's article regarding the 3 big lifts.
-Thought that full ROM increases PFP compression, it's wrong. Partial squats have more compression on the PFJ especially within 90-100 degrees.
-Springing out of the bottom of the squat can increase forces through the knee and could potentially lead to knee pain with excessive loads over a long period of time. This is because the highest forces and muscular tension during a squat occur from the eccentric – concentric phases as muscle lengthening is much higher during full ROM.
-Full ROM squats supervised with consideration of these factors do not cause knee damage.
-Sprinters and jump height seemed to increase more with partial squat instead of full ROM
-Full ROM provides better results for general strength and conditioning.
-However due to higher loads placed on the joints, can be subjected to developing hip and knee pain.
-Increased squat depth and wider stance has been shown to increase glute activation.
-Front squat and back squat had the same glute activation levels
-Peak quadriceps activation is within 80-90 degrees and did not increase its activation as the depth increased (Old theory was the VM did not activate until you went past 90).
-Higher VMO activation with partial squat (33%) than a full squat (18-20%), sumo stance does NOT change the activation levels.
-The hamstring does not change in length because it the hip flexes on the decent.
-Hamstring activity is increased on the ascent the squat within the ranges of 50-70 degrees of knee flexion.
-Body weight squat hamstring activation is minimal and won’t increase until minimal 12 reps.
-Hamstring activity has show to have the highest activation during a hack squat and flat back wall squat. Full ROM and partial ROM has the same activity levels.
-Gastrocnemius had the highest activation at 60-90 knee flexion and minimal-to-none on the ascent.
-Putting the gastrocnemius directly under the hips during a wall sit increased its activity.
-Adding squats to a resistance training program has bee shown to reduce age related conditions such as sarcopenia and dynapenia (The loss of muscular strength not caused by neurological or muscular disease that typically is associated with older adults).
-Simultaneously activates multiple muscle groups throughout the body which results in a significant amount of stress and the MSK system and may initiate several systemic adaptations.
-Compared to a squat, deadlifts require force production without the aid of the stretch-shortening cycle (Deadlift starts with a concentric and ends with an eccentric contraction (Squat is opposite).
-The squat has viscoelastic energy to be stored on the way down to explode on the way up. The deadlift starts in a mechanically difficult position due to requiring a large amount of force need to move the bar off the floor without the stretch short cycle.
-Load is applied perpendicular to the body and loaded in the horizontal plane, unlike the squat which is loaded in the vertical plan.
-Horizontal loaded movements may be more beneficial for sporting movements such as sprinting and long jump due to it being in the same plane increasing the efficiency of load transfer and potentially improving sports performance.
-The deadlift appears to be whole body exercise and has several biomechanical differences to the squat, and potential benefit to sporting performance.
-The deadlift recruits several muscle groups and high contraction rates.
-Posses a favourable kinetic profile that allows for a continued acceleration through a large portion of the lift which contributes to developing power.
-Uses bent leg position and a vertical trunk position.
-Back lift technique comprises of hips raising up first the followed by the legs, increasing trunk flexion angle exposing higher loads within the lumbar.
-Leg lifting technique produces higher forces though the knee joint, reducing the risk of developing back related injuries.
-Researches have suggested that the deadlift recruits muscle groups synergistically to create muscle forces to lift the bar off the ground. Its also observed that lifters change their technique from leg lift to back lift when the wright appears to be very heavy.
-Some researchers have said that the leg lift technique may not be the preferred method of technique with heavy loads (NO CHANCE)
-Deadlifts utilise muscles of both the lower limb and the upper limb.
-At the start of the lift, the gastrocnemius and soleus and plantar flexing, producing a concentric contraction as the bar is coming up.
-Quads contract to extend the knee and glute max beings to contract as the knee extended.
-In the trunk the obliques, TA, QL and rectus abdominus contract to maintain spine stability.
-The ES concentrically contract to bring the spine back in to neutral position.
-Scapulae stability prevents upper back from rounding forward which is supported by the contraction of the lat dorsi.
-Strength and conditioning coaches believe that grip strength plays a big role in performance, however no research has been reported between grip strength and deadlift performance.
-Most research suggests wider grip on the bar improves the performance of the movement, reducing the bar travel time. The bar has been shows to travel 25% more with a neutral grip then a wider grip.
-However, with the wider grip there is an increased risk of pectoral injury, shoulder instability injuries and clavicle injuries – this is assuming they are bench completely flat.
-Elite powerlifters have found that lifting the bar in line with the shoulders has been more beneficial.
-Many other chest accessory work has been shown to have positive effects on improving bench performance due to increased overall strength.
-Some research suggests that different angles of the bench target different parts of the pec major (incline – upper, flat – middle, decline – lower), however some other research suggest there is no difference in activation of the clavicle head (upper) with incline or flat bench.